What is a Case Report Form (CRF)?
A Case Report Form (CRF) is an important study document for the structured collection of data during the conduct of a study (see also ISO 20916 Annex A.5 and Annex H.16).
All study-relevant information on each recruited subject or patient is recorded in the CRF, forming the basis for subsequent data analysis and the study report. Accordingly, data must be documented accurately, completely, and traceably.
To protect the data subjects, the data is collected in an anonymised or, where applicable, pseudonymised manner.
Paper CRF and eCRF
Data can be collected either on paper or electronically via an eCRF (electronic Case Report Form). Electronic systems provide structured data entry forms, plausibility checks, and audit trails.
Requirements for (e)CRFs:
- Legibility: All entries must be clearly legible and complete, and must be made in permanent ink.
- Corrections: Incorrect entries must be corrected in such a way that the original value remains legible (single strikethrough, date, initials of the person making the corrections).
- Completeness: All intended fields must be completed; missing values must be explained (e.g., “not collected”, “not applicable”).
- Storage: (e)CRFs must be protected against loss, damage, and unauthorised access and retained in accordance with applicable regulatory retention periods.
- Validation: (e)CRF systems must be reviewed in accordance with a validation plan prior to use (e.g., functional and security testing, with documentation of validation results).
- Data integrity: Systems must be operated to ensure data is protected against unauthorised access, loss, alteration, or destruction (access controls, backups, encryption).
- Traceability: All changes must be version-controlled and fully traceable via an audit trail, including time, user, and reason.
- Data protection: Anonymisation or pseudonymisation of data and role-based access control are mandatory.
- Compliance: Processes align with ISO 20916 (clinical performance studies with human specimens).
Get in touch if you would like to find out more about CRFs and how to develop them for your study. We are happy to help!
Ulrich Sonner, Team Lead Biostatistics & Data Management
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Abbreviations
CRF: Case Report Form
eCRF: electronic Case Report Form
ISO: International Organization for Standardisation

